Figure. Actigraphic data for three typical successive nights for a “ very active” boy aged 4 and an “inactive” boy as rated by their nursery teachers. 1) Actigraphic data of a “very active” boy aged 4. The mean activity over three days for the “very active” child was 547 counts. The highest number of activity counts for a single sampling epoch was 6069 during the study period. 2) Actigraphic data of an “ inactive” boy aged 4. The mean activity over three days for the “inactive” child was 121 counts. The highest number of activity counts for a single sampling epoch was 3589 during the study period. Activity: leg activity data compressed to one-minute epoch, diurnal time, 5 am through 7 pm; nocturnal time, 7 pm through 5 am.